Usually, there are some problems involved with operating carriages or strollers, such as unwanted movement of the carriage that cannot be controlled completely by any wheel of the carriage. In order to make a convenient brake, to avoid unwanted movement of the carriage, and to make the design of the carriage safer, the applicant of this invention has previously filed Chinese utility model patent application No. 96222862.1 in the Chinese patent office on Sep. 2, 1996, and entitled "Universal, Directional and Brake Mechanism Integrated in a Single Unit." According to this application, every wheel of the carriage can occupy three states, i.e. a universal or swivel state, a directional state and a directional-brake state. Transfer of the wheel between states can easily be accomplished by foot. The device shown in the above-identified application has been constructed to settle the above problems by making it easy to operate, quick to control, and safe to use. In many practices, however, the problems also found are:
First, the pedal arm is fixed together with the vertical shaft by molded plastic and therefore strength is required to step on the pedal, and usually the wheel must be turned to an optimum position which is suitable for stepping on;
Second, it's not very quick and convenient when the brake arm of the brake shoe sticks in the wheel rib when restoring the wheel to its former freewheeling state.